Boris Johnson’s hopes of getting Commons backing for his Brexit deal have hit a major stumbling block after MPs voted for an amendment which could force him to seek another delay.

But a defiant Mr Johnson responded to the vote by telling MPs: “I will not negotiate a delay with the EU and neither does the law compel me to do so.

”In a special Saturday sitting, the Commons voted by 322 to 306, majority 16, in favour of the amendment by the former Cabinet minister Sir Oliver Letwin withholding approval until legislation to implement the deal is in place.

The vote on the Brexit deal between the UK and the EU was not held following the Letwin amendment.

Sir Oliver, one of the MPs to have the Tory whip withdrawn after rebelling on Brexit, said it was an “insurance policy” intended to ensure the UK cannot “crash out” of the EU on October 31 without a deal.

Under the terms of the so-called Benn Act, if he does not have agreement on a deal on Saturday, the Prime Minister is required to seek a further extension to the Article 50 withdrawal process until the end of January.

Ministers have signalled that they will press ahead with plans to table the legislation next week with a view to securing Britain’s departure by the end of the month.

Mr Johnson told the Commons after the vote: “It has been a very important debate, an exceptional moment for our country, an exceptional moment for our Parliament.

“Alas, the opportunity to have a meaningful vote has effectively been passed up because the meaningful vote has been voided of meaning.

“But I wish the House to know that I am not daunted or dismayed by this particular result and I think it probably became likely once it became obvious that the amendment from my right honourable friend, the member for West Dorset was going to remain on the order paper.

“I continue in the very strong belief that the best thing for the UK, and for the whole of Europe is for us to leave with this new deal on October 31, and to anticipate the questions that are coming from the benches opposite, I will not negotiate a delay with the EU.

”Labour leader Jeremy Corbyn replied: “I welcome today’s vote. It’s an emphatic decision by this house that has declined to back the Prime Minister’s deal today, and clearly voted to stop a no-deal crash out from the European Union.

“The Prime Minister must now comply with the law. He can no longer use the threat of a no-deal crash out to blackmail members to support his sell out deal.”